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From: tip-bot for Peter Zijlstra <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@kernel.org,
	peterz@infradead.org, tglx@linutronix.de
Subject: [tip:locking/core] futex: Cleanup variable names for futex_top_waiter()
Date: Thu, 23 Mar 2017 11:19:11 -0700	[thread overview]
Message-ID: <tip-499f5aca2cdd5e958b27e2655e7e7f82524f46b1@git.kernel.org> (raw)
In-Reply-To: <20170322104151.554710645@infradead.org>

Commit-ID:  499f5aca2cdd5e958b27e2655e7e7f82524f46b1
Gitweb:     http://git.kernel.org/tip/499f5aca2cdd5e958b27e2655e7e7f82524f46b1
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Wed, 22 Mar 2017 11:35:48 +0100
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 23 Mar 2017 19:10:06 +0100

futex: Cleanup variable names for futex_top_waiter()

futex_top_waiter() returns the top-waiter on the pi_mutex. Assinging
this to a variable 'match' totally obscures the code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: juri.lelli@arm.com
Cc: bigeasy@linutronix.de
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: jdesfossez@efficios.com
Cc: dvhart@infradead.org
Cc: bristot@redhat.com
Link: http://lkml.kernel.org/r/20170322104151.554710645@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 kernel/futex.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 45858ec..1531cc4 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1122,14 +1122,14 @@ static int attach_to_pi_owner(u32 uval, union futex_key *key,
 static int lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
 			   union futex_key *key, struct futex_pi_state **ps)
 {
-	struct futex_q *match = futex_top_waiter(hb, key);
+	struct futex_q *top_waiter = futex_top_waiter(hb, key);
 
 	/*
 	 * If there is a waiter on that futex, validate it and
 	 * attach to the pi_state when the validation succeeds.
 	 */
-	if (match)
-		return attach_to_pi_state(uval, match->pi_state, ps);
+	if (top_waiter)
+		return attach_to_pi_state(uval, top_waiter->pi_state, ps);
 
 	/*
 	 * We are the first waiter - try to look up the owner based on
@@ -1176,7 +1176,7 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
 				struct task_struct *task, int set_waiters)
 {
 	u32 uval, newval, vpid = task_pid_vnr(task);
-	struct futex_q *match;
+	struct futex_q *top_waiter;
 	int ret;
 
 	/*
@@ -1202,9 +1202,9 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
 	 * Lookup existing state first. If it exists, try to attach to
 	 * its pi_state.
 	 */
-	match = futex_top_waiter(hb, key);
-	if (match)
-		return attach_to_pi_state(uval, match->pi_state, ps);
+	top_waiter = futex_top_waiter(hb, key);
+	if (top_waiter)
+		return attach_to_pi_state(uval, top_waiter->pi_state, ps);
 
 	/*
 	 * No waiter and user TID is 0. We are here because the
@@ -1294,11 +1294,11 @@ static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q)
 	q->lock_ptr = NULL;
 }
 
-static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
+static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *top_waiter,
 			 struct futex_hash_bucket *hb)
 {
 	struct task_struct *new_owner;
-	struct futex_pi_state *pi_state = this->pi_state;
+	struct futex_pi_state *pi_state = top_waiter->pi_state;
 	u32 uninitialized_var(curval), newval;
 	DEFINE_WAKE_Q(wake_q);
 	bool deboost;
@@ -1319,11 +1319,11 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
 
 	/*
 	 * It is possible that the next waiter (the one that brought
-	 * this owner to the kernel) timed out and is no longer
+	 * top_waiter owner to the kernel) timed out and is no longer
 	 * waiting on the lock.
 	 */
 	if (!new_owner)
-		new_owner = this->task;
+		new_owner = top_waiter->task;
 
 	/*
 	 * We pass it to the next owner. The WAITERS bit is always
@@ -2633,7 +2633,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
 	u32 uninitialized_var(curval), uval, vpid = task_pid_vnr(current);
 	union futex_key key = FUTEX_KEY_INIT;
 	struct futex_hash_bucket *hb;
-	struct futex_q *match;
+	struct futex_q *top_waiter;
 	int ret;
 
 retry:
@@ -2657,9 +2657,9 @@ retry:
 	 * all and we at least want to know if user space fiddled
 	 * with the futex value instead of blindly unlocking.
 	 */
-	match = futex_top_waiter(hb, &key);
-	if (match) {
-		ret = wake_futex_pi(uaddr, uval, match, hb);
+	top_waiter = futex_top_waiter(hb, &key);
+	if (top_waiter) {
+		ret = wake_futex_pi(uaddr, uval, top_waiter, hb);
 		/*
 		 * In case of success wake_futex_pi dropped the hash
 		 * bucket lock.

  reply	other threads:[~2017-03-23 18:21 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-22 10:35 [PATCH -v6 00/13] The arduous story of FUTEX_UNLOCK_PI Peter Zijlstra
2017-03-22 10:35 ` [PATCH -v6 01/13] futex: Cleanup variable names for futex_top_waiter() Peter Zijlstra
2017-03-23 18:19   ` tip-bot for Peter Zijlstra [this message]
2017-03-24 21:11   ` Darren Hart
2017-03-22 10:35 ` [PATCH -v6 02/13] futex: Use smp_store_release() in mark_wake_futex() Peter Zijlstra
2017-03-23 18:19   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-24 21:16   ` [PATCH -v6 02/13] " Darren Hart
2017-03-22 10:35 ` [PATCH -v6 03/13] futex: Remove rt_mutex_deadlock_account_*() Peter Zijlstra
2017-03-23 18:20   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-24 21:29   ` [PATCH -v6 03/13] " Darren Hart
2017-03-24 21:31     ` Darren Hart
2017-03-22 10:35 ` [PATCH -v6 04/13] futex,rt_mutex: Provide futex specific rt_mutex API Peter Zijlstra
2017-03-23 18:20   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-25  0:37   ` [PATCH -v6 04/13] " Darren Hart
2017-04-06 12:15     ` Peter Zijlstra
2017-04-06 17:02       ` Darren Hart
2017-04-05 15:02   ` Darren Hart
2017-04-06 12:17     ` Peter Zijlstra
2017-04-06 17:08       ` Darren Hart
2017-03-22 10:35 ` [PATCH -v6 05/13] futex: Change locking rules Peter Zijlstra
2017-03-23 18:21   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-05 21:18   ` [PATCH -v6 05/13] " Darren Hart
2017-04-06 12:28     ` Peter Zijlstra
2017-04-06 15:58       ` Joe Perches
2017-04-06 17:21       ` Darren Hart
2017-03-22 10:35 ` [PATCH -v6 06/13] futex: Cleanup refcounting Peter Zijlstra
2017-03-23 18:21   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-05 21:29   ` [PATCH -v6 06/13] " Darren Hart
2017-03-22 10:35 ` [PATCH -v6 07/13] futex: Rework inconsistent rt_mutex/futex_q state Peter Zijlstra
2017-03-23 18:22   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-05 21:58   ` [PATCH -v6 07/13] " Darren Hart
2017-03-22 10:35 ` [PATCH -v6 08/13] futex: Pull rt_mutex_futex_unlock() out from under hb->lock Peter Zijlstra
2017-03-23 18:22   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-05 23:52   ` [PATCH -v6 08/13] " Darren Hart
2017-04-06 12:42     ` Peter Zijlstra
2017-04-06 17:42       ` Darren Hart
2017-03-22 10:35 ` [PATCH -v6 09/13] futex,rt_mutex: Introduce rt_mutex_init_waiter() Peter Zijlstra
2017-03-23 18:23   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-05 23:57   ` [PATCH -v6 09/13] " Darren Hart
2017-03-22 10:35 ` [PATCH -v6 10/13] futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock() Peter Zijlstra
2017-03-23 18:23   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-07 23:30   ` [PATCH -v6 10/13] " Darren Hart
2017-04-07 23:35     ` Darren Hart
2017-03-22 10:35 ` [PATCH -v6 11/13] futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock() Peter Zijlstra
2017-03-23 18:24   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-04-08  0:55   ` [PATCH -v6 11/13] " Darren Hart
2017-04-10 15:51   ` alexander.levin
2017-04-10 16:03     ` Thomas Gleixner
2017-04-14  9:30       ` [tip:locking/core] futex: Avoid freeing an active timer tip-bot for Thomas Gleixner
2017-03-22 10:35 ` [PATCH -v6 12/13] futex: futex_unlock_pi() determinism Peter Zijlstra
2017-03-23 18:24   ` [tip:locking/core] futex: Futex_unlock_pi() determinism tip-bot for Peter Zijlstra
2017-04-08  1:27   ` [PATCH -v6 12/13] futex: futex_unlock_pi() determinism Darren Hart
2017-03-22 10:36 ` [PATCH -v6 13/13] futex: futex_lock_pi() vs PREEMPT_RT_FULL Peter Zijlstra
2017-03-23 18:25   ` [tip:locking/core] futex: Drop hb->lock before enqueueing on the rtmutex tip-bot for Peter Zijlstra
2017-04-08  2:26   ` [PATCH -v6 13/13] futex: futex_lock_pi() vs PREEMPT_RT_FULL Darren Hart
2017-04-08  5:22     ` Mike Galbraith
2017-04-10  8:43     ` Sebastian Andrzej Siewior
2017-04-10  9:08     ` Peter Zijlstra
2017-04-10 16:05       ` Darren Hart
2017-03-24  1:45 ` [PATCH -v6 00/13] The arduous story of FUTEX_UNLOCK_PI Darren Hart

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